11-8
Free Play Check ▶
Start the engine and place the wheels at
straight ahead direction.
Turn the steering wheel until the tires starts
to move and measure the distance on the
circumference of the steering wheel. A.
B.
Free play30 mm
If the free play is out of the specified value,
check the free play in steering column shaft
connection and steering linkage. Replace or
repair if necessary.
Steering Effort Check ▶
Park the vehicle on a paved and flat ground
and place the front wheels at straight ahead
direction.
Start the engine and let it run around 1,000
rpm.
Install the spring scale on the circumference of
the steering wheel and measure the steering
effort in both directions. A.
B.
C.
Steering effort in
standstillbelow 3.0 kg
The difference between both sides should
be within 0.6 kg.
Steering Angle Check ▶
Place the front wheel on a turning radius
measuring tool.
Turn the steering wheel to the both ends and
measure the maximum steering angle. A.
B.
Steering
angleInner36.4°
Outer31.5°
If the steering angle is out of the specified
value, check and adjust the toe-in.
12-8
When the vehicle is driven on a road surface covered with water at high speed, tires do not contact
with the road surface but rotate floating on a thin film of water.
It causes brake failure, lower traction force and losing the steering performance.
To prevent this, increase the tire inflation pressure, use tires with leaf shape tread which is not worn.
However, it is a best measure to drive slowly.
2) Hydroplaning
12-94170-01
If weight is not equally distributed around the wheel, unbalance centrifugal force by the wheel rotation
produces vibration. As the centrifugal force is produced proportional to the square of the rotating
speed, the wheel weight should be balanced even at high speed. There are two types of the tire and
wheel balancing: static and dynamic. Abnormal vibration may also occur due to unbalanced rigidity or
size of tires.
1) Static Balance
When the free rotation of the wheel is
allowed, the heavier part is stopped on the
bottom if the wheel weight is unbalanced
and this is called "Static Unbalance". Also,
the state at which tire's stop position is not
same is called "Static Balance" when the
wheel is rotated again. If the part A is heavie
r
as shown in the figure 1, add the balance
weight of a weight corresponding to
unbalanced weight from B to A to maintain
the static balance. If the static balance is not
maintained, tramping, up and down vibration
of the wheels, occurs.
2) Dynamic Balance
The static unbalance of the wheel creates
the vibration in the vertical direction, but
the dynamic unbalance creates the
vibration in the lateral direction. As shown
in the figure 2 (a), if two parts, (2) and (3),
are heavier when the wheels are under the
static balance condition, dynamic
unbalance is created, resulting in shimmy,
left and right vibration of the wheels, and
the torque Fxa is applied in the axial
direction. To correct the dynamic
unbalance, add the balance weight of a
same weight for two points of the
circumference of the rim, A and B, as
shown in the figure 2 (b), and apply the
torque in the opposite direction to the
torque Fxa to offset in order to ensure
smooth rotation of the wheel.
Center
a
a
Fxa
Fxa F
F
A
B
(a)(b)
[Figure 1]
[Figure 2]
3. WHEEL BALANCE
